1 /*
2 * dir.c
3 *
4 * PURPOSE
5 * Directory handling routines for the OSTA-UDF(tm) filesystem.
6 *
7 * CONTACTS
8 * E-mail regarding any portion of the Linux UDF file system should be
9 * directed to the development team mailing list (run by majordomo):
10 * linux_udf@hpesjro.fc.hp.com
11 *
12 * COPYRIGHT
13 * This file is distributed under the terms of the GNU General Public
14 * License (GPL). Copies of the GPL can be obtained from:
15 * ftp://prep.ai.mit.edu/pub/gnu/GPL
16 * Each contributing author retains all rights to their own work.
17 *
18 * (C) 1998-2001 Ben Fennema
19 *
20 * HISTORY
21 *
22 * 10/05/98 dgb Split directory operations into it's own file
23 * Implemented directory reads via do_udf_readdir
24 * 10/06/98 Made directory operations work!
25 * 11/17/98 Rewrote directory to support ICBTAG_FLAG_AD_LONG
26 * 11/25/98 blf Rewrote directory handling (readdir+lookup) to support reading
27 * across blocks.
28 * 12/12/98 Split out the lookup code to namei.c. bulk of directory
29 * code now in directory.c:udf_fileident_read.
30 */
31
32 #include "udfdecl.h"
33
34 #include <linux/string.h>
35 #include <linux/errno.h>
36 #include <linux/mm.h>
37 #include <linux/slab.h>
38
39 #include "udf_i.h"
40 #include "udf_sb.h"
41
42 /* Prototypes for file operations */
43 static int udf_readdir(struct file *, void *, filldir_t);
44 static int do_udf_readdir(struct inode *, struct file *, filldir_t, void *);
45
46 /* readdir and lookup functions */
47
48 struct file_operations udf_dir_operations = {
49 read: generic_read_dir,
50 readdir: udf_readdir,
51 ioctl: udf_ioctl,
52 fsync: udf_fsync_file,
53 };
54
55 /*
56 * udf_readdir
57 *
58 * PURPOSE
59 * Read a directory entry.
60 *
61 * DESCRIPTION
62 * Optional - sys_getdents() will return -ENOTDIR if this routine is not
63 * available.
64 *
65 * Refer to sys_getdents() in fs/readdir.c
66 * sys_getdents() -> .
67 *
68 * PRE-CONDITIONS
69 * filp Pointer to directory file.
70 * buf Pointer to directory entry buffer.
71 * filldir Pointer to filldir function.
72 *
73 * POST-CONDITIONS
74 * <return> >=0 on success.
75 *
76 * HISTORY
77 * July 1, 1997 - Andrew E. Mileski
78 * Written, tested, and released.
79 */
80
udf_readdir(struct file * filp,void * dirent,filldir_t filldir)81 int udf_readdir(struct file *filp, void *dirent, filldir_t filldir)
82 {
83 struct inode *dir = filp->f_dentry->d_inode;
84 int result;
85
86 if ( filp->f_pos == 0 )
87 {
88 if (filldir(dirent, ".", 1, filp->f_pos, dir->i_ino, DT_DIR) < 0)
89 return 0;
90 filp->f_pos ++;
91 }
92
93 result = do_udf_readdir(dir, filp, filldir, dirent);
94 UPDATE_ATIME(dir);
95 return result;
96 }
97
98 static int
do_udf_readdir(struct inode * dir,struct file * filp,filldir_t filldir,void * dirent)99 do_udf_readdir(struct inode * dir, struct file *filp, filldir_t filldir, void *dirent)
100 {
101 struct udf_fileident_bh fibh;
102 struct fileIdentDesc *fi=NULL;
103 struct fileIdentDesc cfi;
104 int block, iblock;
105 loff_t nf_pos = filp->f_pos - 1;
106 int flen;
107 char fname[255];
108 char *nameptr;
109 uint16_t liu;
110 uint8_t lfi;
111 loff_t size = (udf_ext0_offset(dir) + dir->i_size) >> 2;
112 struct buffer_head * bh = NULL, * tmp, * bha[16];
113 lb_addr bloc, eloc;
114 uint32_t extoffset, elen, offset;
115 int i, num;
116 unsigned int dt_type;
117
118 if (nf_pos >= size)
119 return 0;
120
121 if (nf_pos == 0)
122 nf_pos = (udf_ext0_offset(dir) >> 2);
123
124 fibh.soffset = fibh.eoffset = (nf_pos & ((dir->i_sb->s_blocksize - 1) >> 2)) << 2;
125 if (inode_bmap(dir, nf_pos >> (dir->i_sb->s_blocksize_bits - 2),
126 &bloc, &extoffset, &eloc, &elen, &offset, &bh) == (EXT_RECORDED_ALLOCATED >> 30))
127 {
128 offset >>= dir->i_sb->s_blocksize_bits;
129 block = udf_get_lb_pblock(dir->i_sb, eloc, offset);
130 if ((++offset << dir->i_sb->s_blocksize_bits) < elen)
131 {
132 if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_SHORT)
133 extoffset -= sizeof(short_ad);
134 else if (UDF_I_ALLOCTYPE(dir) == ICBTAG_FLAG_AD_LONG)
135 extoffset -= sizeof(long_ad);
136 }
137 else
138 offset = 0;
139 }
140 else
141 {
142 udf_release_data(bh);
143 return -ENOENT;
144 }
145
146 if (!(fibh.sbh = fibh.ebh = udf_tread(dir->i_sb, block)))
147 {
148 udf_release_data(bh);
149 return -EIO;
150 }
151
152 if (!(offset & ((16 >> (dir->i_sb->s_blocksize_bits - 9))-1)))
153 {
154 i = 16 >> (dir->i_sb->s_blocksize_bits - 9);
155 if (i+offset > (elen >> dir->i_sb->s_blocksize_bits))
156 i = (elen >> dir->i_sb->s_blocksize_bits)-offset;
157 for (num=0; i>0; i--)
158 {
159 block = udf_get_lb_pblock(dir->i_sb, eloc, offset+i);
160 tmp = udf_tgetblk(dir->i_sb, block);
161 if (tmp && !buffer_uptodate(tmp) && !buffer_locked(tmp))
162 bha[num++] = tmp;
163 else
164 brelse(tmp);
165 }
166 if (num)
167 {
168 ll_rw_block(READA, num, bha);
169 for (i=0; i<num; i++)
170 brelse(bha[i]);
171 }
172 }
173
174 while ( nf_pos < size )
175 {
176 filp->f_pos = nf_pos + 1;
177
178 fi = udf_fileident_read(dir, &nf_pos, &fibh, &cfi, &bloc, &extoffset, &eloc, &elen, &offset, &bh);
179
180 if (!fi)
181 {
182 if (fibh.sbh != fibh.ebh)
183 udf_release_data(fibh.ebh);
184 udf_release_data(fibh.sbh);
185 udf_release_data(bh);
186 return 0;
187 }
188
189 liu = le16_to_cpu(cfi.lengthOfImpUse);
190 lfi = cfi.lengthFileIdent;
191
192 if (fibh.sbh == fibh.ebh)
193 nameptr = fi->fileIdent + liu;
194 else
195 {
196 int poffset; /* Unpaded ending offset */
197
198 poffset = fibh.soffset + sizeof(struct fileIdentDesc) + liu + lfi;
199
200 if (poffset >= lfi)
201 nameptr = (char *)(fibh.ebh->b_data + poffset - lfi);
202 else
203 {
204 nameptr = fname;
205 memcpy(nameptr, fi->fileIdent + liu, lfi - poffset);
206 memcpy(nameptr + lfi - poffset, fibh.ebh->b_data, poffset);
207 }
208 }
209
210 if ( (cfi.fileCharacteristics & FID_FILE_CHAR_DELETED) != 0 )
211 {
212 if ( !UDF_QUERY_FLAG(dir->i_sb, UDF_FLAG_UNDELETE) )
213 continue;
214 }
215
216 if ( (cfi.fileCharacteristics & FID_FILE_CHAR_HIDDEN) != 0 )
217 {
218 if ( !UDF_QUERY_FLAG(dir->i_sb, UDF_FLAG_UNHIDE) )
219 continue;
220 }
221
222 if ( cfi.fileCharacteristics & FID_FILE_CHAR_PARENT )
223 {
224 iblock = udf_get_lb_pblock(dir->i_sb, UDF_I_LOCATION(filp->f_dentry->d_parent->d_inode), 0);
225 flen = 2;
226 memcpy(fname, "..", flen);
227 dt_type = DT_DIR;
228 }
229 else
230 {
231 iblock = udf_get_lb_pblock(dir->i_sb, lelb_to_cpu(cfi.icb.extLocation), 0);
232 flen = udf_get_filename(dir->i_sb, nameptr, fname, lfi);
233 dt_type = DT_UNKNOWN;
234 }
235
236 if (flen)
237 {
238 if (filldir(dirent, fname, flen, filp->f_pos, iblock, dt_type) < 0)
239 {
240 if (fibh.sbh != fibh.ebh)
241 udf_release_data(fibh.ebh);
242 udf_release_data(fibh.sbh);
243 udf_release_data(bh);
244 return 0;
245 }
246 }
247 } /* end while */
248
249 filp->f_pos = nf_pos + 1;
250
251 if (fibh.sbh != fibh.ebh)
252 udf_release_data(fibh.ebh);
253 udf_release_data(fibh.sbh);
254 udf_release_data(bh);
255
256 return 0;
257 }
258